U.S. Pat. No. 5,395,490 describes a method of altering the physical characteristics of keratinic fibers utilizing electromagnetic radiation of a particular frequency. The technique described in U.S. Pat. No. 5,395,490 disrupts the disulfide bonds in keratinic fibers by electromagnetic radiation that has a frequency corresponding to the natural resonant frequency of the disulfide bond.
It is also well known that the disulfide bonds (S--S) in keratinic fibers can be disrupted by treating the fibers with various reactive chemicals. For example, conventional permanent waving of hair treats hair with sulfur reducing agents such as thioglycolic acid, thioglycerol, thioacetic acid or mercaptoethanol to break the disulfide bonds (For example, see book entitled "Chemical and Physical Behavior of Human Hair" by C. R. Robbins, 1994). Treatment with these chemicals is usually followed by treatment with a neutralizing agent such as peroxide to reestablish the disulfide bonds. All of the conventionally used chemicals for permanently waving hair have various disadvantages. For example some of the chemicals damage the hair and leave it feeling harsh. Others require mixing immediately prior to use since they hydrolyze on contact with water. Also, they are all reactive compounds and begin reacting as soon as they are applied to the hair, making even application difficult, and the desired resultant uniform hair reduction over the whole head complicated.
It has also been suggested that ring forming dithiols are effective in disrupting disulfide bonds to permanently wave hair. For example see U.K. Patent 1,260,227. However, ring forming dithiols have not previously achieved any significant commercial success as chemicals for permanently waving.
Attempts have been previously made to effect the hair reduction and neutralization reactions in a single operation (For example, see book entitled "The Science of Hair Care", C. Zviak (ed.), Vol. 7, Dermatology Series, pg. 194-195, 1986). Such a self-neutralizing system would simplify the process, achieve a permanent wave in a single step, and save considerable time. Unfortunately, none of the techniques previously investigated has led to a satisfactory self-neutralizing system that doesn't require the peroxide neutralization step, or its equivalent.